The first photocrystallographic evidence for light-induced metastable linkage isomers of ruthenium sulfur dioxide complexes

Light-induced metastable linkage isomers of trans-[Ru(NH(3))(4)Cl(SO(2))]Cl and trans-[Ru(NH(3))(4)(H(2)O)(SO(2))](C(6)H(5)SO(3))(2) have been identified for the first time using photocrystallographic methods. In both linkage isomers the SO(2) ligand is side bound, but the Ru-O and Ru-S distances are considerably longer and almost equal in the trans-H(2)O isomer. DFT calculations confirm that both isomers correspond to minima on the ground-state potential energy surface and also predict the existence of a second oxygen-bound isomer for both compounds. The decay of the light-induced species has been studied by both DSC and IR. Activation energies for the thermal back-reaction, as derived from the temperature-dependent disappearance of light-induced IR bands, are 50.0 and 58.4 kJ/mol for the two isomers, which is larger than the corresponding numbers for photoinduced side-bound nitrosyl linkage isomers.     

Application of Horner–Emmons Olefination to the Crown-Ether Derivatives

An effective synthetic approach to the preparation of a new crown-ether vinylogs involving the Horner–Emmons olefination of carbonyl precursors with the use of C₂- and C₅-phosphonates was proposed. The effects of the conjugation chain length and the nature of the terminal polar functions in the phosphonate reagent on the yield and process stereoselectivity were discussed.     

Geometry changes of a Cu(I) phenanthroline complex on photoexcitation in a confining medium by time-resolved X-ray diffraction

Using a stroboscopic technique, in which the molecule is repeatedly excited and the structural change is probed more than 5000 times per second immediately after excitation, we performed a 16 K time-resolved single-crystal study of the microsecond lifetime triplet state of the Cu(I)phenanthroline derivative[Cu(I)(dmp)(dppe)][PF6] (dppe = 1,2-bis(diphenylphosphino)ethane). The geometry changes on excitation differ for the two symmetry-independent molecules, but are in the same direction as calculated for an isolated reference molecule, although the flattening distortion in the crystal is significantly smaller, implying that the reorganization energy is greatly affected by the confining medium.     

Express detection of nonylphenol in water samples by fluorescence polarization immunoassay

The development of express method for detection of endocrine-disrupting chemicals (EDC) such as alkylphenols is required for ecological monitoring. Several attempts have been made to produce antibodies against 4-nonylphenol (NP) in recent years. This work describes the production of new antibodies against NP and also summarizes the characterization of antibodies obtained earlier. Three approaches used to produce alkylphenol-specific antibodies are compared; these are based on: 1. omega-(4-hydroxyphenyl)nonanoic or omega-(4-hydroxyphenyl)heptanoic acid NP derivatives designed to mimic the linear NP isomer; 2. 4-aminophenol, which potentially mimics various substituted phenolic compounds with different side-chain structures at position 4 of the benzene ring; and 3. a mixture of branched NP isomers, conjugated to the carrier protein via a benzene ring by the Mannich reaction, and expected to be the closest mimic of NP structure by preserving its natural alkyl moiety.Fluorescence polarization immunoassays based on different combinations of antibody and labeled antigen for screening detection of NP were developed and structural aspects of assay sensitivity and specificity were investigated. The assays based on the antisera raised against omega-(4-hydroxyphenyl)nonanoic acid and NP conjugate via Mannich reaction are capable of express detection of NP with detection limit of 7 microg mL(-1 )and assay dynamic range of 18-300 microg mL(-1).     

Diamondoid Nanostructures as sp3‐Carbon‐Based Gas Sensors

Diamondoids, sp³‐hybridized nanometer‐sized diamond‐like hydrocarbons (nanodiamonds), difunctionalized with hydroxy and primary phosphine oxide groups, enable the assembly of the first sp³‐C‐based chemical sensors by vapor deposition. Both pristine nanodiamonds and palladium nanolayered composites can be used to detect toxic NO₂ and NH₃ gases. This carbon‐based gas sensor technology allows reversible NO₂ detection down to 50 ppb and NH₃ detection at 25–100 ppm concentration with fast response and recovery processes at 100 °C. Reversible gas adsorption and detection is compatible with 50 % humidity conditions. Semiconducting p‐type sensing properties are achieved from devices based on primary phosphine–diamantanol, in which high specific area (ca. 140 m² g^?1) and channel nanoporosity derive from H‐bonding.     

An unexpected mechanism of hydrosilylation by a silyl hydride complex of molybdenum

Carbonyl hydrosilylation catalyzed by (ArN)Mo(H)(SiH(2)Ph)(PMe(3))(3) (3) is unusual in that it does not involve the expected Si-O elimination from intermediate (ArN)Mo(SiH(2)Ph)(O(i)Pr)(PMe(3))(2) (7). Instead, 7 reversibly transfers β-CH hydrogen from the alkoxide ligand to metal.